The original liquid is regarded as a mixture.
A mixture is regarded as a material which comprises of two or more
substances which are combined physically. An example is the mixture of
dye and water.
A compound on the other hand is combined chemically and not physically
which when exposed to the same type of situation either remains in the
beaker or nothing at all is found. Since the water evaporates and a green
solid was present then it means the material was a solution in which
water(solvent) and the green solid(solute) was physically combined and not
chemically combined together.
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